The subject matter disclosed herein relates to coke and lignite gasification. More specifically, disclosed embodiments of the invention relate to preparation of feed slurries prior to gasification.
Fossil fuels, such as coal or petroleum, may be gasified for use in the production of electricity, chemicals, synthetic fuels, or for a variety of other applications. Gasification involves reacting a carbonaceous fuel and oxygen at a very high temperature to produce syngas, a fuel containing carbon monoxide and hydrogen, which burns much more efficiently and cleaner than the fuel in its original state.
Different carbonaceous fuels may be gasified with varying success. That is, a higher heat value generally indicates that a fuel is more easily combustible. The heat value of a material is a measure of the energy released by combustion of the fuel with oxygen. For example, petcoke, which is produced from cracking petroleum, has a relatively high heat value and, therefore, is easily gasified. In contrast, lignite, which has high moisture and high ash content, has a very low heat content and is therefore difficult to gasify. In some instances, lignite contains too much moisture and ash to gasify. However, lignite is much less expensive than coke, which must be derived (i.e., cracked) prior to gasification. Accordingly, it may be desirable to develop a system and process by which lignite and coke may be gasified together.